Locking arrangement for engagement tool

ABSTRACT

A locking mechanism for elongate tools that are designed to engage objects from remote distances and that have engagement elements located on a distal end of a rod, a handle on a proximate end of the rod, a controller on the handle to control the engagement elements, and a linkage between the controller and the engagement elements to control the engagement elements is disclosed. The locking elements include a saw tooth receiving surface that is rigidly affixed to a trigger and a stop member having complementary saw tooth extensions. A switch member controls the movement of the stop member into engagement and out of engagement with the receiving surface which thereby locks and unlocks the movement of the trigger.

This invention relates to an improvement for tools designed to engage objects from remote distances. This is a division of U.S. application Ser. No. 10/302,861. The applicant claims the benefit of the filing date of U.S. Provisional Application No. 60/384,820 and U.S. application Ser. No. 10/302,861.

BACKGROUND OF THE INVENTION

There are a wide variety of tools designed for picking up objects or manipulating objects from a distance. One common application for such tools is use by maintenance workers to pick-up debris for subsequent disposal. A tool with an elongate handle allows manipulation of the object without the need to bend over or to directly handle the material. Such tools are also useful for individuals that have physical handicaps that may impede their ability to bend over and reach the ground. There are also numerous household applications for such tools including retrieval of materials from high shelves or from under furniture. Another common application for such tools is for changing light bulbs from recessed lighting fixtures. Another entire class of devices that operate in a similar manner and perform a similar function as the pick-up tools described above are marketed as toys. Other tools may have blades on the distal end for cutting that may be used for a wide range of uses including those tools used in the surgical field and tools used for trimming high branches.

Common elements that are shared by such devices that are addressed by the improvement disclosed herein include (1) an elongate shaft having (2) a handle on one end and, (3) engagement elements on the opposite end, (4) a controller element on the handle and (5) a linkage from the controller element to the engagement elements. The user of the these tools may manipulate a controller, such as a lever or trigger, that is provided on the handle end of the device to operate the engagement elements that are provided on the opposite end of the elongate shaft. The engagement elements may include arrangements such as claws, arms, scoops, calipers, tongs, blades or cups. In typical designs, the control lever pulls an internal linkage that draws together the engagement elements that are biased apart by springs.

Exemplary arrangements of such devices are disclosed in the U.S. Pat. No. 4,962,957 (the “'957 Patent”), U.S. Pat. No. 4,709,839 (the “'839 Patent”), U.S. Pat. No. 3,527,492 (the “'492 Patent”), U.S. Pat. No. 4,613,179 (The '179 Patent), U.S. Pat. No. 4,669,769 (the '769 Patent) and U.S. Pat. No. 6,257,634 (the '634 Patent).

A desirable feature that is sometimes incorporated on these devices is a locking mechanism that enables the engagement elements to be retained in a fixed position. A locking features allows a user of the device to retain the engagement elements in a closed position and in contact with an object and thereby allow a user to release pressure on the controller while maintaining control over the object. Consequently, a user can use his or her free hand to further manipulate the object, either directly, or indirectly by using the elongate shaft. Allowing the user to release pressure on the controller yet maintain engagement of the object also adds a convenience feature.

There have been a number of alternative manners to accomplish locking engagement elements on grabber tools that are disclosed in the prior art. For example, the patent to Moyer, U.S. Pat. No. 1,120,735, discloses a segment that can be manipulated by a lever that in turn may be secured in place by a pawl. The pawl is biased against the ratchet segment by a leaf spring. The '957 patent discloses an alternative manner in which to lock the engagement elements of a pick-up tool that allows the trigger to be released while maintaining pressure on the object. U.S. Pat. No. 5,823,590 to Forrest et al. discloses yet another alternative method of locking the engagement elements thereby allows a user to manually secure the central linkage in fixed position. U.S. Pat. No. 6,438,891 to Aboczky provides a spring locking mechanism.

While, there exist numerous types of devices and a variety of alternative manners in which to lock engagement elements in fixed positions, many of the efforts disclosed in the prior art have involved fairly complex arrangements and require multiple parts. In general, increased complexity of a proposed device is associated with increased expense in connection with manufacturing and with respect to the costs of the parts required to achieve the feature. Accordingly, there continues to remain a demand and a commercial market for devices that have a simple and inexpensive locking arrangement. A further desirable feature to provide with elongate engagement tools is the ability for the device to fold or collapse. Because these devices employ an elongate rod, the devices are somewhat cumbersome in connection with shipping, handling, display and storage. While it is desirable to provide a manner in which to collapse the device, the manner in which the collapse is affected must accommodate the linkage between the controller and engagement elements and must also maintain sufficient strength to support objects when the elongate member is in an extended position. While the prior art has recognized this need, there remains room for improved alternative and effective manners to achieve these goals. In this regard, for example, U.S. Pat. No. 4,613,179 relies upon a stop pin 71 that is designed to work only when the device is in an upright position. U.S. Pat. No. 5,823,590 discloses a telescopic arrangement to collapse a grabber device. U.S. Pat. No. 4,231,603 discloses a grabber device with a hinge fixture that allows the proximal and distal ends of an elongate rod to be aligned in different directions.

It is an object of the present invention to provide a new locking arrangement for the engagement elements of a pick-up tool that is simple to manufacture and assemble and that uses only a few parts. A further object of the present invention is to provide an engagement device that has a locking device that can be easily manipulated by the user. A further objective of the invention is to provide a locking hinge on the elongate arm or rod that allows the devices to fold yet maintain strength when in an extended position.

SUMMARY OF THE INVENTION

The present invention relates to both a new locking arrangement and a folding hinge structure for the engagement of such devices described above. The invention allows the user of such a device to engage an object and then manipulate a sliding switch to lock the engagement elements in a fixed position. The switch causes a stop member, oriented in a direction transverse to the switch, to engage a control surface and prevent movement of the controller. The switch is provided on the handle so that it can be manipulated by the user's thumb while he or she operates the controller for the device. The control surface is fixed and integrated with the controller that controls the engagement elements that are positioned on the opposite end of an elongate rod. The device also incorporates a hinge feature on the elongate rod that enables the elongate arm to be folded in half so that the device may be shipped and stored conveniently. The hinge, which is provided at a midpoint along the elongate rod, does not significantly diminish the strength of the rod. The hinge uses a pin that has axial sections that alternate from sections having a circular profile to sections having an aster shaped profile. The pin may be aligned in a first locked position wherein the aster shaped segment fit into corresponding aster shaped cavities within the knuckle that prevents the leaves from movement. The pin may be positioned to occupy an alternate second position wherein the sections of the pin having a round profile is aligned in the aster profiled cavity thereby allowing the leaves to pivot with respect to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the pick-up device according to the invention;

FIG. 2 is a perspective view of the device shown folded about the hinge;

FIG. 3 is an exploded view of the handle of the invention;

FIG. 4 is a bottom view in elevation of the switch element used with the locking feature of the invention;

FIG. 5 is a perspective view of the switch element used with the locking feature of the invention;

FIG. 6 is an exploded view of the hinge element of the invention;

FIG. 7 is a bottom view of the exterior segment of the pin used with the hinge element of the invention.

FIG. 8 is a side view in elevation of the exterior segment of the pin used in connection with the hinge element of the invention.

FIGS. 9 and 10 are embodiments of FIG. 1 showing a cable which connects trigger 16 to the engagement elements.

DETAILED DESCRIPTION

Now referring to FIG. 1, a preferred embodiment of the elongate grabber tool 8 is depicted in an extended position. Grabber tool 8 incorporates engagement cups 10 on a distal end of a elongate hollow rod 12 and a pistol grip 14 on the opposite proximal end. A trigger 16 is provided adjacent to pistol grip 14 for manipulation by a user's fingers. As shown on the side of pistol grip 14, a switch 18 is provided that effects a locking feature of the engagement elements of the device. At a medial point on elongate hollow rod 12 is hinge 20 that allows elongate rod 12 to fold. FIG. 2 depicts the rod in a folded position wherein the distal end of elongate rod 12 is folded back on the top side and adjacent to pistol grip 14.

Now referring to FIG. 3, trigger 16 extends from and is connected to the handle at axis or pivot point 30 that is located near the top of the pistol grip 14. A connecting pin 32 transects handle side 25 a, the trigger half 16 a, trigger half 16 b and handle side 25 b. Trigger 16 extends through a slot or opening provided between the forward sides of pistol grip 14 and allows for limited pivotal movement with respect to the axis 30. As seen on trigger side 16 b, a cavity is provided to retain a nipple (not shown) which is provided on the end of a cable shown in figures 9 and 10 as element 300 a and 300 b) that connects trigger 16 to the engagement elements on the distal end of the tool. The engagement elements, which are biased apart by spring members 31 are drawn together by pulling connector members 29 toward the handle 14 via the central cable. Control surface 35 is an arcuate notched surface that is integral with trigger half 16 a and on which is provided a series of saw-tooth notches 38. The arc is formed so that each saw tooth extension is approximately equidistant to the pivot point 30. The notches 38 are adapted to receive the end projections 40 of a stop member 42. Stop member 42 is engaged or disengaged by the lateral manipulation of switch 44. Stop member 42 also is provided with a pin member 48 that is engaged by switch 44. Stop member 42 can be disengaged by either movement of the switch in the opposite direction or by application of a force against the trigger that will push the stop member from its position. Stop member 42 is locked into place and in engagement with notches 38 on the arcuate control surface 35 by use of a mechanical locking engagement wherein switch 44 stays in position by frictional engagement.

FIGS. 4 and 5 depict the rear side of switch 44. As best seen in FIG. 5 extensions 60, 61, 62 and 63 have a projections that extend laterally away from the extensions so that the switch 44 will snap fit into opening 50 and be retained within the opening. For example, surface 70 of projection 60 will engage the interior surface of the handle side 25 a adjacent to the opening 50. Since the projections only extend toward the top and bottom of the switch, the arrangement allows for the lateral movement of the switch 44 within opening 50. Walls 65 and 67 define groove 72 into which the pin member 48 of stop member 42 is received. Lateral movement of switch causes the side walls 65 and 67 to move pin 48 thereby causing the stop member to move up or down and in or out of engagement with the control surface 35.

In operation, a user can use the device in a manner that allows free movement of cups or, by manipulation of the switch can cause the stop member to engage the notches on the trigger and therefore lock the movement of the device. The stop member can be disengaged by pulling on the trigger, which forces the teeth 40 of stop member 42 out of engagement with the opposite teeth 38 on control surface 35. The teeth 40 may also be disengaged from the opposite teeth 38 on control surface 35 by lateral movement of switch 44.

While an integral saw-toothed notched control surface 35 is depicted as a preferred embodiment, it is contemplated that other arrangements could be advantageously employed to lock the trigger. For example, a side view of the control surface could resemble a round or square waveform that has an opposite and complementary profile of teeth provided on a stop member. In a further contemplated embodiment, the control surface may be comprised of a series of cavities that have sidewalls oriented transverse to the control surface and the stop member includes an extension that can be received in the cavities. For example, in this alternative contemplated embodiment, a series of annular cavities are provided on the control surface that can receive a peg that extends from the stop member. In yet further contemplated embodiments of the invention the stop member is made of conical shaped projections or pyramid shaped projections that are received in opposite and complementary shaped cavities.

The locking arrangement according to the invention uses only a few parts and can therefore be economically manufactured and assembled. As described herein, the locking feature further allows for the stop member to engage the control surface along the entire range of motion of the control surface 35 and range of the trigger 16. The switch for the lock can be manipulated by the user's thumb while the handle 25 of the device is held in the user's hand.

While the controller depicted in the preferred embodiment is a trigger designed to be engaged by multiple fingers of the user, the applicant contemplates that alternative arrangements of the trigger or controller may also be provided. For example, in an alternative embodiment the trigger may be manipulated by a user's single finger. In yet another contemplated alternative embodiment, the trigger may be displaced on the rear side of the stationary handle. Further, while in the preferred embodiment the engagement elements are opposite engagement cups, it is also contemplated that other engagement elements may also be used and that may depend on the intended application.

As best shown in FIG. 6, in a preferred embodiment of the invention the elongate shaft is provided in two sections, a distal section 101 and a proximal section 103. The distal section 101 and the proximal section 103 are connected by a locking hinge structure 105 that enables the device to be folded. Hinge 105 includes a forward hinge section composed of opposite halves 111 a and 111 b and a rearward section composed of opposite halves 120 a and 120 b. Halve 120 a includes a shank 135 and two flat knuckle sections 137 and 139 that extend from shank 135. Separating knuckle section 137 from section 139 is a gap that has an axial dimension about the same distance as the as the width of one of the respective knuckles. This distance is also approximately the same as the length of sections 182 and 184 of the hinge pin.

The knuckle sections 115 and 118 extend from the distal end of the hinge segment 111 and are positioned on the exterior lateral sides of the hinge. When assembled, sections 115 and 137 are adjacent to one another and define a portion of an axial channel that extends transverse to the direction of the elongate rod. When the grabber device is in its extended position, wall 201 comes into contact with wall 203 and prevents further rotation in one direction.

The hinge pin is made of exterior section 170 and a retention member 172. Retention member includes rounded head section 172 on the end of shank member 175. Shank member 175 of retention member 172 is received in opposite and complementary cavity 178 that is provided in the exterior section 170. As seen in FIGS. 7 and 8 the exterior shank section 179 has a number of sections along its axial length. As best seen in FIG. 7, a bottom view of the exterior section 170, section 185 has an aster or “star shaped” axial section. Sections 183 and 181 of the pin have the same star shaped profile. Separating the star shaped sections are sections 182 and 184 that have circular or round axial sections. As best seen in FIG. 6 the exterior section of the pin is inserted through the axial cavity formed when the knuckles are aligned.

The arrangement described above allows the hinge pin to be positioned in alternative positions including a first position wherein the rounded axial sections 182 and 184 of the pin are aligned within knuckle sections 137 and 139. In this first position the hinge section is allowed to rotate about the pin. Application of pressure on the rounded head allows the pin to be moved in an axial direction through the channel to a second position where the are locked with respect. In the locked position the star shaped axial sections 181, 183 and 185 of pin 170 are aligned within the aster shaped cavities defined by the knuckles 115, 135, 139 and 118. In this position the front leaf section does not move with respect to the rearward leaf section.

The hinge allows the device to be positioned in the extended position as depicted in FIG. 1 or in the folded position as depicted in FIG. 2. When the device is in the extended position, the hinge may be locked into position wherein the hinge leaves are fixed with respect to one another.

While the preferred embodiments have been described herein, those skilled in the art will recognize that certain details may be changed without departing from the spirit and scope of the invention. Thus, the foregoing specific embodiments and applications are illustrative only and are not intended to limit the scope of the invention. It is contemplated that the invention will functional and effective in diverse applications where it is desirable to lock elements that are designed to engage or otherwise manipulate objects from a remote distance. Likewise, although the locking hinge structure is particularly useful in connection with elongate grabber tools, the hinge may also be employed on other rod statures where there is need. 

1. An improvement for elongate tools that are designed to engage objects from remote distances and that have engagement elements located on a distal end of a rod, a handle on a proximate end of said rod, a controller on said handle to control said engagement elements, and a linkage between said controller and said engagement elements to control said engagement elements, said controller further comprises a trigger member and said trigger member is attached to said handle, said improvement comprising a lock member, said lock member comprising a receiving surface and a stop member, said receiving surface extending from said trigger member and adapted to receive said stop member, and said receiving surface attached to said trigger member in a rigid and fixed relationship, wherein said receiving surface comprises a series of adjacent saw-tooth shaped extensions and said stop member comprises at least one opposite complementary saw-tooth extension wherein when said extension from said stop member engages said receiving surface, said receiving surface is restricted from lateral movement with respect to said stop member thereby causing said trigger member to lock said lock member further comprising a switch member, said switch member connected to said stop member to control the movement of said stop member, wherein in response to movement of said switch member, said stop member either engages or disengages said receiving surface wherein when said stop member is engaged with said receiving surface the movement of said trigger member is prevented and when said stop member is disengaged from said receiving surface said trigger member is allowed to be displaced.
 2. The improvement for an elongate tool as recited in claim 1, wherein said trigger member is attached to said handle in a manner to allow for pivotal movement.
 3. The improvement for an elongate tool as recited in claim 1, wherein said receiving surface is integrally formed with said trigger member.
 4. The improvement for an elongate tool as recited in claim 1 wherein said switch member is located on said handle at a location that can be manipulated by a users thumb when said user is holding the handle and engaging the trigger member with fingers.
 5. The improvement as recited in claim 1 wherein said switch member is in a slideable engagement with said handle and when said switch member is slid, it mechanically translates said sliding motion to said stop member causing said stop member to engage and disengage said receiving surface.
 6. The improvement as recited in claim 5 wherein said motion is transferred from said switch member to said stop member by a camming engagement.
 7. The improvement as recited in claim 1 further comprising a hinge element located on said rod between said engagement elements and said trigger member.
 8. The improvement as recited in claim 1 wherein said engagement elements comprise opposite cup shaped members.
 9. The improvement as recited in claim 1 wherein said linkage comprises a cable and said cable is connected to said trigger member and said engagement elements.
 10. The improvement as recited in claim 9 wherein said linkage is contained within said rod and one end of said linkage is attached to said trigger member.
 11. The improvement as recited in claim 1 further comprising biasing means, wherein said biasing means bias said engagement elements apart.
 12. An improvement for elongate tools that are designed to engage objects from remote distances and that have engagement elements located on a distal end of a rod, a handle on a proximate end of said rod, a controller on said handle to control said engagement elements, and a linkage between said controller and said engagement elements to control said engagement elements, said controller further comprises a trigger member and said trigger member is attached to said handle, said improvement comprising a lock member, said lock member comprising a receiving surface and a stop member, said receiving surface extending from said trigger member and adapted to receive said stop member, and said receiving surface attached to said trigger member in a rigid and fixed relationship, said lock member further comprising a switch member, wherein said switch member is connected to said stop member to control the movement of said stop member, wherein in response to movement of said switch member, said stop member either engages or disengages said receiving surface wherein when said stop member is engaged with said receiving surface the movement of said trigger member is prevented and when said stop member is disengaged from said receiving surface said trigger member is allowed to be displaced, and wherein said switch member is in a slideable engagement with said handle and when said switch member is slid, it mechanically translates said sliding motion to said stop member causing said stop member to engage and disengage said receiving surface, wherein said motion is transferred from said switch member to said stop member by a camming engagement.
 13. The improvement for an elongate tool as recited in claim 12 wherein said trigger member is attached to said handle in a manner to allow for pivotal movement.
 14. The improvement for an elongate tool as recited in claim 12, wherein said receiving surface is integrally formed with said trigger member.
 15. The improvement for an elongate tool as recited in claim 12, wherein said switch member is located on said handle at a location that can be manipulated by a users thumb when said user is holding the handle and engaging the trigger member with fingers.
 16. The improvement as recited in claim 12, wherein said switch member is in a slideable engagement with said handle and when said switch member is slid, it mechanically translates said sliding motion to said stop member causing said stop member to engage and disengage said receiving surface.
 17. The improvement as recited in claim 16, wherein said motion is transferred from said switch member to said stop member by a camming engagement.
 18. The improvement as recited in claim 12, further comprising a hinge element located on said rod between said engagement elements and said trigger member.
 19. The improvement as recited in claim 12, wherein said engagement elements comprise opposite cup shaped members.
 20. The improvement as recited in claim 12, wherein said linkage comprises a cable and said cable is connected to said trigger member and said engagement elements.
 21. The device as recited in claim 20, wherein said linkage is contained within said rod and one end of said linkage is attached to said trigger member.
 22. The improvement as recited in claim 12, further comprising biasing means, wherein said biasing means bias said engagement elements apart. 